I'm an aspiring Manga-ka and Graphic designer... XD I'm working on improving my anatomy so please bear with me! I know I'm not the best artist out there far from it but I like to think of myself as relatively good ^^

It could be the nib if you are using a tablet... Just throwing that out there! If you got a replacement pen tip it might work! Otherwise my only advice is to reinstall the software for the tablet...
Hope your stuff gets working again! 8D